Insertion reactions of the C-B-N-substituted borinium cation [MesBNiPr2].

The synthesis and isolation of the first stable C-B-N-substituted borinium [MesBNiPr2][B(C6F5)4] (2) is described. Compound 2 was shown to react with isothiocyanate and carbodiimides, effecting B-C insertion to afford nitrilium (4) and borenium amidinate salts, respectively. The borinium cation [MesBNiPr2]+ (2+) was also generated from reactions of MesB(Cl)NiPr2 (1) and GaCl3, and used to prepare stable borenium amidinate salts (5-6), while the triflate borane MesB(OTf)NiPr2 (7) reacts with carbodiimide to give the bis(amidinate) boronium salt [MesC(NiPr)2B((NiPr)2C)NiPr2][OTf] (8).